Ice buildup in traditional ultra-low temp freezers is a significant obstacle to effective utilization of the freezing area. As ice builds up inside the freezer, less and less samples can be stored. Also, existing samples are covered in hard cake ice making sample retrieval harder and harder till such a point as the freezer is shut down, forcing a deicing protocol. This maintenance uses valuable staff labor time, delays lab activities and mostly puts frozen samples in jeopardy of being accidently warmed up, destroying the samples. Removing this type of ice has been demonstrated to be an advantage to users in multiple freezer applications.
Floor space utilization is a key factor to bio-sample storage facilities. The higher the sample density, the lower the operational costs for the facility. So it is to the user's advantage to be able to store as many samples as possible in the smallest of space possible.
Traditional mechanical freezers do not address this issue. Attempts at improving the freezer insulation, adding compartment doors that limit in-rush ambient air and adding refrigeration capacity have not successfully solved the issue of internal icing. The problem has been that none of these attempts delve far enough into the actual cause of the ice issues, The base issue is water vapor condensing throughout the interior surfaces. The exterior insulation technique uses only an open cell foam which lacks in thermal performance. Internal doors lack the mechanical and insulative precision. Heat gain around the door edges allows for ambient air to flow into the interior area.
Other challenges to traditional mechanical refrigeration are rejected heat and internal monitoring. As with any mechanical refrigeration process, the heat removed from the interior along with the heat created by performing this task need to be rejected. Typically this rejected heat is passed to the ambient area around the freezer. This requires more floor space and a significant increase in room HVAC capacity, especially in multi-freezer applications. This can leave users with very hot freezer rooms which significantly increases operating electrical expenses. Also, because of the larger footprint needed, freezer density is reduced. Which leads to larger and larger freezer rooms being required.